Liming Yu
Jun Peng
Chieko Mineo- 1Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, United States
- 2Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, United States
Sialylation is a dynamically regulated modification, which commonly occurs at the terminal of glycan chains in glycoproteins and glycolipids in eukaryotic cells. Sialylation plays a key role in a wide array of biological processes through the regulation of protein–protein interactions, intracellular localization, vesicular trafficking, and signal transduction. A majority of the proteins involved in lipoprotein metabolism and atherogenesis, such as apolipoproteins and lipoprotein receptors, are sialylated in their glycan structures. Earlier studies in humans and in preclinical models found a positive correlation between low sialylation of lipoproteins and atherosclerosis. More recent works using loss- and gain-of-function approaches in mice have revealed molecular and cellular mechanisms by which protein sialylation modulates causally the process of atherosclerosis. The purpose of this concise review is to summarize these findings in mouse models and to provide mechanistic insights into lipoprotein sialylation and atherosclerosis.
Introduction
Sialic acids are a family of negatively charged carbohydrates, which are commonly found as terminal residues of an oligosaccharide chain of glycoproteins or glycolipids in the eukaryotic cells. The terminal sialylation plays a key role in diverse biological functions, including the regulation of leukocyte–endothelial cells interaction, signal transduction, and maintenance of normal protein conformation and intracellular transport (1–8). Aberrant sialylation has been implicated in several diseases, including cancer, pathogen infection, and cardiovascular disease (CVD) (9–11). Previous reports in large cohorts have found that high serum levels of sialic acid, both protein-bound and free forms, are an independent risk factor for CVD (12, 13). Other studies have shown a positive relationship between plasma total sialic acid levels and severity or complications of CVD (14–16), while two reports have failed to find such associations (17, 18). Many apolipoproteins, including apolipoprotein B (ApoB), apolipoprotein C-III (ApoC-III), and apolipoprotein (ApoE) are highly glycosylated, with sialic acids being the predominant terminal residues (19–23). The addition or removal of sialic acid in apolipoproteins is regulated by a group of enzymes, namely, neuraminidases (also known as sialidases) and sialyltransferases, and an alteration of expression or activity of these enzymes are known to influence lipoprotein metabolism and atherogenesis (24–26). Increased neuraminidase activity has been described in the plasma of patients after myocardial infarction compared with that in healthy controls (27). Upregulation of sialyltranferase activity has also been shown in atheroma and in the plasma from individuals with atherosclerosis compared to heathy donors (28). However, it is entirely unknown whether these changes in the enzyme activities impact circulating levels of sialic acids or sialylation of proteins related to the atherogenesis in humans.
ApoB is the main structural component of very-low-density lipoprotein (VLDL) and low-density lipoprotein (LDL), and it contains a number of glycosylation sites, majority of which are modified with complex N-linked glycans with sialic acid as terminal residue (29). Earlier works demonstrated that patients with CVD or type 2 diabetes (T2DM) have elevated levels of plasma LDL containing lower amounts of sialic acids compared to healthy individuals (19, 30). These hyposialylated LDL particles have been characterized as smaller in size with an increased electronegative charge, containing more triglyceride (TG), fatty acid, and oxysterols compared to normally sialylated LDL (31–34). Mechanistically, desialylated-LDL particles generated by neuraminidase treatment ex vivo were more readily taken up by cells isolated from human aortas than native LDL, leading to increased intracellular accumulation of cholesterol ester (25, 35, 36). Both conventional scavenger receptors and galactose-specific lectin receptors such as asialoglycoprotein receptors (ASGRs), which recognize terminal galactose residues that are exposed after desialylation, have been implicated to facilitate uptake of desialylated LDL (25, 35, 36). Desialylated LDL is also shown to be highly immunogenic, and it can induce the production of proatherogenic autoantibodies (32, 37–39). More recent studies in cultured cells found that neuraminidase-mediated desialylation of high-density lipoprotein (HDL) particles impairs their ability to mediate reverse cholesterol transport (RCT) (35, 40).
ApoC-III is another apolipoprotein in which a relationship between its sialylation status and capacity to regulate lipid metabolism is well established. ApoC-III is mainly synthesized in the liver, and in the circulation, it is carried by VLDL and chylomicrons, along with LDL and HDL (11, 41). ApoC-III plays a key role in the regulation of TG metabolism through the inhibition of lipoprotein lipase (LPL), hepatic receptor-mediated clearance of TG-rich lipoproteins (TRL), and promotion of VLDL production, and a direct correlation has been established between circulating levels of ApoC-III and CVD (42–44). ApoC-III is modified with O-linked glycan with multiple molecules of sialic acid at the termini (21). Three major glycoforms (or “sialoforms”) are known, referred to as ApoC-III0b, ApoC-III1, and ApoC-III2 containing 0, 1, and 2 molecules of sialic acid per molecule of protein, respectively. In plasma, the non-glycosylated form of ApoC-III (ApoC-III0a) is present at very low levels, with glycosylated forms (both non-sialylated and sialylated) representing majority of circulating ApoC-III (45). A number of studies demonstrated that the relative abundance of ApoC-III sialoforms are altered under various pathological conditions, including obesity, metabolic syndrome, diabetes, hyperlipidemia, and CVD (44–47). A correlation has been also reported between higher levels of ApoC-III1 and an atherogenic lipid profile, including increased levels of plasma total cholesterol, LDL-cholesterol, TG, and decreased levels of ApoAI (46). This report did not find any differences in the relative abundance of the three sialoforms in their ability to inhibit LPL activity, and it remains unclear how the sialylation impacts the function of ApoC-III. However, one study indicated that different ApoC-III sialoforms may influence the clearance of TRL in the liver (48). Hepatic TRL clearance is mediated by heparan sulfate proteoglycan syndecan-1, LDL receptor (LDLR), and LDLR-related protein 1 (LRP1) (49–53). The study found that LDLR and LRP1 rapidly clear TRL containing ApoC-III1, whereas ApoC-III2 is more slowly cleared by the heparan sulfate proteoglycan syndecan-1 (48). Furthermore, individuals with a loss-of-function mutation in the gene encoding polypeptide N-acetylgalactosaminyltransferase 2 (GALNT2), an enzyme involved in the glycosylation of ApoC-III, displayed sixfold increase in the levels of ApoC-III0 with a reduction in ApoC-III1, and they displayed an improved postprandial TG clearance (54).
ApoE is another glycosylated apolipoprotein that is found in various lipoproteins, including HDL, VLDL, and LDL (55). ApoE is synthesized and secreted by many cell types, including hepatocytes, smooth muscle cells, and macrophages, and it is involved in cholesterol transport and metabolism as a surface component of the lipoprotein particles (56, 57). ApoE proteins are highly O-glycosylated with terminal sialic acid residues (58–60). It is reported that desialylation of ApoE by ex vivo neuraminidase treatment lowers its affinity for HDL (61). This work further demonstrated that reconstituted HDL containing desialylated ApoE has lower ability to facilitate esterified cholesterol uptake in HepG2 cells and that enzymatic re-sialylation of desialylated-ApoE by sialyltransferases restores capacities to bind HDL and to take up esterified cholesterol to the levels comparable to intact ApoE (61). In addition, a potential contribution of negative charges attributed to terminal sialylation of ApoE has been implicated in the atherogenic nature of electronegative L5 LDL (62–64).
These observations collectively demonstrate the importance of sialylation in modulating lipoprotein metabolism and cardiovascular disease phenotypes in human. However, how changes in sialylation of the lipoproteins regulate the processes in the atherosclerosis and cardiovascular diseases are yet to be fully understood. Aiming to provide novel insights into the potential basis for contribution of apolipoprotein sialylation in atherosclerosis, this review focuses on the published works, in which the well-established hyperlipidemia-induced atherosclerosis mouse models were used in combination with clear gain- or loss-of-function approaches in vivo. More comprehensive reviews on protein or lipid glycosylation in lipid metabolism and atherosclerosis can be found elsewhere (11, 65, 66). A number of excellent reviews are also available that provide in-depth discussion of the biology of sialic acids and their binding partners and functions of the enzymes involved in sialylation processes in human health and diseases (10, 67–70).
Mouse models of sialylation and atherosclerosis
Administration of N-acetylneuraminic acids
A few studies demonstrated that administration of N-acetylneuraminic acid (NANA), a major form of sialic acid in mammals (71), decreases atherosclerosis in hyperlipidemic mouse models (72, 73). Guo et al. first reported (72) that NANA administration in Apoe−/− mice decreased atherosclerotic plaque formation and lipid accumulation in the liver. The reduction in atherosclerosis was associated with upregulation of hepatic proteins related to RCT, such as ATP-binding cassette transporter (ABC)G1 and ABCG5 and with downregulation of inflammatory markers. More recently, Hou et al. also showed that NANA supplementation in Apoe−/− mice enhances RCT, indicated by increased [3H]-cholesterol transfer from [3H]-cholesterol-loaded macrophages to the plasma, liver, and feces for excretion (73). This improvement of RCT in the latter work was associated with upregulation of ABCG1 and peroxisome-proliferator-activated receptor α (PPARα) in the liver.
Neuraminidases
Neuraminidases (also known as sialidases) catalyze the removal of terminal sialic acids from glycoproteins, oligosaccharides, and glycolipids, and there are four mammalian subtypes of neuraminidases (NEU1–4) that show distinct, but overlapping, tissue expression, intracellular localization, and substrate specificity (74, 75). As described above, hyposialylation of lipoproteins is closely associated with atherosclerosis, and the neuraminidases are likely responsible for producing the hyposialylated forms of LDL and HDL. In addition, the enzymes may play a role in vascular inflammation in an earlier step of atherogenesis. Both NEU1 and NEU3 are expressed in human endothelial cells, and NEU1 levels negatively correlate with a capacity of endothelial cells to migrate (76). Neuraminidase-mediated removal of sialic acids from leukocyte β2‐integrin or endothelial adhesion molecule ICAM1 has been shown to enhance interaction between leukocytes and endothelial cells, contributing to proatherogenic vascular inflammation (77).
Impacts of gain- or loss-of-function manipulation of neuraminidases on cardiovascular phenotypes in mice have been reported by several groups. NEU1 is mainly expressed in lysosome and in the plasma membrane of mammalian cells (78, 79). The contribution of NEU1 in atheroprotection in mice has been first recognized as a key component of atherogenic action of elastin-derived peptide (EP) (80). EP is produced by protease degradation of the extracellular matrix of the arterial wall, and it shows multiple proatherogenic effects, including stimulation of monocyte migration, production of reactive oxygen species and oxidized LDL, and vascular smooth muscle cell proliferation (81–83). EP exerts these effects by activating the elastin receptor complex (ERC), which is composed of an elastin-binding protein, cathepsin A, and NEU1. In particular, NEU1 has been identified as the protein critically involved in signal transduction induced by ERC in various cell type (84–86). Gayral et al. (80) found that Apoe−/− or Ldlr−/− mice injected with EP have increased fatty streak lesions, without modifying plasma cholesterol levels. An involvement of NEU1 in atherogenesis was further investigated in NEU1-deficient mice with cathepsin A hypomorph (CathAS190A‐Neo), which shows a 90% reduction in NEU1 activity without developing severe sialidosis-like phenotypes associated with complete NEU1 knockout mice (87–89). Using bone marrow (BM) transplantation from CathAS190A-Neo to Ldlr−/−-recipient mice, they showed that the mice with decreased NEU1 in hematopoietic lineage cells had decreased atheroma formation and leukocytes infiltration (80). These results suggest that specific activation of ERC by EP containing NEU1 in macrophages contributes to atherosclerosis.
To directly test whether NEU1 impacts atherosclerosis, White et al. (90) employed the mice with reduced NEU1 activity caused by the mutations in NEU1 gene (hypomorphic Neu1) (91, 92). In this study, the hypomorphic Neu1 mice on Apoe−/− background (Neu1hypoApoe−/−) showed a reduced atherosclerotic lesion compared with the Apoe−/− mice (90). The lesion in Neu1hypo;Apoe−/− mice displayed fewer macrophages, T cells, and smooth muscle cells, implying attenuation of inflammation and cell recruitment within the plaque. Serum total cholesterol levels associated with VLDL and LDL were lower, and hepatic cholesterol content was decreased in Neu1hypoApoe−/− mice, associated with a lower production rate of VLDL-TG, compared to Apoe−/− mice. BM transplant experiments were further performed to determine the contribution of NEU1 in hematopoietic cells. Transplantation of Apoe−/− BM into Neu1hypo;Apoe−/− mice led to an increased atherosclerotic-lesion compared with transplantation of Neu1hypo;Apoe−/− BM. The hepatic and serum lipid levels were not different between Neu1hypo;Apoe−/− mice transplanted with BM from Apoe−/− and Neu1hypoApoe−/− donors. Furthermore, compared with that in control mice, tumor necrosis factor alpha (TNFα) treatment results in reduced leukocyte–endothelial cell interaction in Neu1hypoApoe−/− mice. The rescue of the neuraminidase expression in vivo by adenovirus-mediated overexpression of NEU1 reduced the leukocyte–endothelial cell interaction. These data indicate NEU1 plays an important role in both leukocyte rolling and adhesion, which are important steps leading to leukocyte extravasation. Moreover, smooth muscle cell content in the aortic sinus of Neu1hypo;Apoe−/− was reduced compared with that of Apoe−/− mice, consistent with reports that NEU1-dependent desialylation increases smooth muscle cell proliferation (83). The reduction in macrophages in the lesion also correlates with a substantial decrease in subsets of neutrophils/granulocytes in the peripheral blood. Heimerl et al. subsequently reported that Neu1hypo mice display decreased left ventricular (LV) dysfunction after ischemia/reperfusion (I/R) injury, along with fewer pro-inflammatory macrophage infiltration (93). Wild-type (WT) mice transplanted with BM derived from Neu1hypo mice and Neu1hypo mice with WT BM both displayed better LV function after I/R compared with WT mice with WT-BM. In contrast, they found that mice with a cardiomyocyte-specific NEU1 overexpression have increased cardiomyocyte hypertrophy and reduced LV dysfunction despite a similar infarct scar size to WT mice after I/R.
More recently, Demina et al. reported that deficiency of NEU1 and NEU3 but not NEU4 attenuates atherosclerosis (94). In this study, NEU1-deficient (CathAS190A‐Neo), Neu3−/− or Neu4−/− mice (87, 95, 96) were crossed with Apoe−/− mice, and atherosclerosis was evaluated. Apoe−/−;CathAS190A‐Neo and Apoe−/−;Neu3−/− mice showed smaller atherosclerotic lesions compared to Apoe−/− mice. Apoe−/−;Neu4−/− had lesion size comparable to Apoe−/− mice. In contrast to the work by White et al. (90), deficiency of NEU1 or NEU3 did not affect plasma LDL cholesterol, TG, or HDL levels. The study showed reduced numbers of macrophages in atherosclerotic lesions in Apoe−/−;CathAS190A‐Neo. Interestingly, macrophage-positive areas in the lesions were similar between Apoe−/−;Neu3−/− and Apoe−/− mice, suggesting that different mechanisms may underlie reduced plaque formation in NEU1‐ versus NEU3‐deficient mice. Parallel observations were made in mice with Ldlr−/− background. The work also confirmed the previous studies that ApoB in human LDL can be desialylated ex vivo by NEU1 and NEU3 and that desialylated LDL is taken up by cultured macrophages. They further demonstrated that BM-derived cells in the culture from ASGR knockout mice (Asgr−/−) display reduced uptake of desialylated LDL compared to those from wild-type mice. In vivo, the injection of fluorophore-labeled desialylated LDL resulted in the incorporation of lipoproteins in liver macrophages in wild-type mice but not in Asgr−/− mice. These results indicate that ASGR is likely involved in desialylated LDL taken into the macrophages, contributing to increased atherosclerosis in NEU1- or NEU3-deficient mice.
In addition to the genetic loss-of-function manipulation of neuraminidases in mice, effects of chemical inhibitors were examined in several studies. White et al. reported (90) that the administration of 2,3‐didehydro‐2‐deoxy‐N‐acetyl‐neuraminic acid (DANA), a broad spectrum neuraminidase inhibitor, in Apoe−/− mice for 6 weeks resulted in the attenuation of hepatic total cholesterol and cholesteryl esters compared with that in vehicle-treated control mice. Aortic sinus lesions from the DANA-treated Apoe−/− mice were reduced compared with that in control mice. They performed additional control experiments using oseltamivir (also known as Tamiflu), a specific inhibitor of influenza virus neuraminidase, which does not effectively inhibit mammalian sialidases, and they found that oseltamivir did not reduce the atherosclerotic plaque formation in male Apoe−/− mice. A lack of effect by oseltaminir on atherosclerosis or thrombosis in Ldlr−/− mice was also recently reported (97). Demina et al. (94) similarly reported that treatment with specific NEU1 and NEU3 inhibitor (98) or more broad NEU1 inhibitor (98, 99) reduced the size of atherosclerotic lesions in Apoe−/− mice. The study found that treatment with the inhibitors did not affect the plasma levels of total cholesterol, LDL-cholesterol, HDL-cholesterol, or TG (94).
Sialyltransferases
Glycosyltransferases are also closely involved in the key events in the early stage of atherosclerosis, including generation of functional selectin ligands and regulation of leukocyte adhesion to the endothelium and subsequent extravasation (100–102). Mammalian sialyltransferases comprise 20 glycosyltransferases that facilitate the transfer of sialic acids to the terminal glycosyl group of glycoproteins and glycolipids (69, 103). Sialic acid is attached to the glycan terminus through three different linkages, namely, α2,3, α2,6, or α2,8, which are formed by the distinct sets of sialyltransferases. As mentioned above, upregulation of plaque and plasma sialyltransferase activity has been reported in patients with atherosclerosis (28). However, whether the enzymes play any role in atherosclerosis remains largely unknown.
One of the sialyltransferases, ST3 β-galactoside α-2,3-sialyltransferase 4 (St3Gal4), catalyzes the transfer of sialic acids in the α2,3 linkage to termini of N- and O-glycans. This sialic acid modification has been implicated in von Willebrand factor (vWF) synthesis and activity (104, 105). An association of single nucleotide polymorphisms (SNPs) in the St3Gal4 gene with plasma levels of vWF was reported in multiple human cohorts after adjustment for confounders such as age, BMI, hypertension, and diabetes (106). These observations suggest a possible role of St3Gal4 in hemostasis and thrombosis. In addition, St3Gal4 is critically required for selectin function, as mice deficient in the enzyme (St3Gal4−/−) displayed an impaired selectin ligand function and attenuated selectin-dependent leukocyte adhesion or rolling induced by various stimuli (107–110). The interaction with selectins and their glycan ligands facilitates leukocyte tethering and rolling on the vascular endothelium, thus contributing to the early phase of atherosclerosis (5, 111). Frommhold et al. (110) reported a major role for St3Gal4-mediated sialylation of the chemokine receptor Cxcr2 in triggering leukocyte arrest on inflamed microvasculature (112). Similarly, C–C chemokine receptor type 5 (Ccr5) binding to its ligands, Ccl3 and Ccl4, was reported to be strongly dependent on a sialic-acid-carrying O-glycan in the N-terminal domain of Ccr5 (113). Doring et al. subsequently showed in Apoe−/− mice that St3Gal4 deficiency reduced the size of atherosclerotic areas and numbers of macrophages in the lesion, without affecting plasma cholesterol levels (112). They further demonstrated that Ccl5-induced neutrophil and monocyte extravasation into the peritoneal cavity was reduced in St3Gal4−/− mice and that St3Gal4 deficiency results in a reduced binding of Ccl5 and an abrogation of Ccl5-induced arrest on TNFα-stimulated endothelium in cell culture and ex vivo experiments.
ST6 β-Galactoside α-2,6-sialyltransferase 1 (St6Gal1) catalyzes the α2,6 linkage to an underlying galactose residue, and its expression and activity are closely associated with the negative regulation of the immune response (114, 115). Genome-wide association studies (GWAS) have revealed that SNPs of St6Gal1 are linked to multiple inflammatory disorders, including CVD and T2DM (116–118). Zhang et al. reported that the St6Gal1 expression in aortic endothelium is inversely related to atheroma formation in Apoe−/− mice (119). In cultured EA.hy926 endothelial cell line, they further showed that siRNA knockdown of St6Gal1 promoted transendothelial migration of monocytes induced by TNFα, whereas overexpression of the enzyme had opposite effect. More recently, Holdbrooks et al. showed that BM-derived macrophages from mice with myeloid-specific St6Gal1 deletion display reduced long-term activation of nuclear factor kappa B (NF-kB) by TNFα or lipopolysaccharide (LPS) (120). Furthermore, in experiments using cultured monocytes, the study implicates TNFR1 or TLR4 to be a potential substrate of St6Gal1-mediated α2-6 sialylation related to the inflammatory regulation by monocytes/macrophages. Impacts of ST6Gal1 on atherosclerosis have not yet been reported in mice; however, Oswald et al. reported (121, 122) that mice with hepatocyte-specific St6Gal1 deletion develop spontaneous hepatic steatosis after 52 weeks on high-fat diet, indicated by the accumulation of fat droplets, inflammatory cytokine production, and presence of pro-inflammatory macrophages in the liver.
Discussion
The loss- and gain-of-function mouse models of sialylation machinery so far have provided a valuable tool to understand the molecular mechanism by which protein sialylation modulates atherosclerosis progression. These works highlight the significant contributions by the enzymes and substrates related to protein sialylation in diverse sets of cell types, including leukocytes, macrophages, endothelial cells, immune cells, and hepatocytes. The loss-of-function studies for neuraminidases demonstrate a major atheroprotective role of lipoprotein sialylation. In contrast, the studies in mice with St3Gal4 deficiency implicate that sialylation of selectin ligands and chemokine receptors likely plays an atherogenic role. These opposing functions of protein sialylation depend upon the target substrate molecules and the locations where the modification is regulated. Recent studies in mice using BM transplantation or monocyte-specific Cre-LoxP system have uncovered the key function of neuraminidases and sialyltransferases in monocytes and macrophages (80, 90, 94, 120, 123). More studies are needed to address the importance of protein sialylation using mice with additional tissue- and cell-type-specific targeting of the machinery, including endothelial cells and vascular smooth muscle cells. Similarly, in addition to the lipoproteins and the selectin ligands, a number of plasma proteins and the lipoprotein receptors are sialylated, and modulation of the sialylation status of these proteins likely play a role in atherogenesis. For example, a recent study found that sialylation of the scavenger receptor CD36 is modulated by NEU1 containing ERC complex in macrophages (124). CD36 is a scavenger receptor expressed on the surface of a wide range of cells, including macrophages, platelets, and microvascular endothelial cells, and CD36 deficiency has profound atheroprotective effects in mice (125, 126); however, whether the sialylation of CD36 contributes to atherogenic effect of ERC is yet to be proven. Another study in humans investigated an association of glycosylation and sialylation traits of plasma immunoglobulin (IgG) with subclinical atherosclerosis (127). The work identified specific traits related to IgG sialylation that are negatively correlated with cardiovascular disease risk, circulating levels of VLDL and TG, and presence of carotid plaque. Increased levels of IgG with low sialylation and glycosylation have been observed in patients with inflammatory diseases such as rheumatoid arthritis and Crohn’s disease (128, 129). In mouse models, increase in IgG sialylation in vivo via provision of the sialic acid precursor or engineered transferases resulted in attenuation of the inflammation-associated disease outcomes (128, 130). Future investigations are warranted to determine whether hyposialylation of IgG plays a similar pathogenic role in atherosclerosis in mouse models or in human.
Finally, close associations between genetic polymorphisms of enzymes and receptors related to sialylation and cardiovascular risks have emerged. For example, in a genetic study of Icelanders, researchers discovered a rare noncoding 12-bp deletion (del12) in the Asgr1 gene that generates a premature stop (131). They found that this variant form of Asgr1 is strongly associated with a decrease in plasma levels of non-HDL cholesterol and TG and with reduced risk for CVD. Mirroring the human phenotype, a recent study showed that Asgr1−/− mice exhibit lower non-HDL-cholesterol and TG caused by decreased secretion and increased uptake of VLDL/LDL (132). Similar approaches combining human genetics with preclinical mouse models will further advance the understanding of how protein sialylation impacts atherosclerosis and CVD. However, a recent report by Kawanishi et al. adds more complexity in application of the findings in non-human models to humans (133). The work demonstrated that a loss of cytidine monophosphate-N-acetylneuraminic acid (Neu5Ac) hydroxylase (CMAH) contributes to the development of atherosclerosis. CMAH catalyzes the generation of N-glycolylneuraminic acid (Neu5Gc) from its precursor Neu5Ac in majority of mammals including mice, but humans lack CMAH due to pseudogenization of the gene, resulting in a species-specific Neu5Gc deficiency in humans (134, 135). Mice with Cmah deficiency, mimicking human-like Cmah pseudogenization, on Ldlr−/− background developed increased atherosclerosis compared to single Ldlr−/− mice (133, 136). The use of the humanized mouse model needs to be taken into consideration for future preclinical studies.
Although an alteration of sialylation in plasma lipoproteins has long been associated with atherosclerosis and CVD, the field of sialylation in atherosclerosis is still in its infancy. Emerging works in mice discussed in this review have established that sialylation is a key mechanism that influences atherosclerosis. Future studies are urgently needed to fill in the major knowledge gaps—paucity of loss-of-function mouse models for additional enzymes and transporters and limited information regarding the sialylated proteins involved in atherosclerosis.
Author contributions
All three authors contributed to reviewing of the literature and writing of the manuscript. All authors contributed to the article and approved the submitted version.
Funding
The work is funded by NIH R01 (5R01DK110127, 5R01DK110127-S1, CM).
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Publisher’s Note
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References
1. Li Y, Chen X. Sialic acid metabolism and sialyltransferases: Natural functions and applications. Appl Microbiol Biotechnol (2012) 94:887–905. doi: 10.1007/s00253-012-4040-1
2. Nie H, Li Y, Sun XL. Recent advances in sialic acid-focused glycomics. J Proteomics (2012) 75:3098–112. doi: 10.1016/j.jprot.2012.03.050
3. Chen X, Varki A. Advances in the biology and chemistry of sialic acids. ACS Chem Biol (2010) 5:163–76. doi: 10.1021/cb900266r
4. Hinek A, Wrenn DS, Mecham RP, Barondes SH. The elastin receptor: A galactoside-binding protein. Science (1988) 239:1539–41. doi: 10.1126/science.2832941
5. McEver RP. Selectins: Lectins that initiate cell adhesion under flow. Curr Opin Cell Biol (2002) 14:581–6. doi: 10.1016/S0955-0674(02)00367-8
6. Frenette PS, Denis CV, Weiss L, Jurk K, Subbarao S, Kehrel B, et al. P-selectin glycoprotein ligand 1 (PSGL-1) is expressed on platelets and can mediate platelet-endothelial interactions in vivo. J Exp Med (2000) 191:1413–22. doi: 10.1084/jem.191.8.1413
7. Krishnamurthy VR, Sardar MY, Ying Y, Song X, Haller C, Dai E, et al. Glycopeptide analogues of PSGL-1 inhibit p-selectin in vitro and in vivo. Nat Commun (2015) 6:6387. doi: 10.1038/ncomms7387
8. Liu YC, Yen HY, Chen CY, Chen CH, Cheng PF, Juan YH, et al. Sialylation and fucosylation of epidermal growth factor receptor suppress its dimerization and activation in lung cancer cells. Proc Natl Acad Sci U.S.A. (2011) 108:11332–7. doi: 10.1073/pnas.1107385108
9. Pinho SS, Reis CA. Glycosylation in cancer: Mechanisms and clinical implications. Nat Rev Cancer (2015) 15:540–55. doi: 10.1038/nrc3982
10. Varki A. Sialic acids in human health and disease. Trends Mol Med (2008) 14:351–60. doi: 10.1016/j.molmed.2008.06.002
11. Pirillo A, Svecla M, Catapano AL, Holleboom AG, Norata GD. Impact of protein glycosylation on lipoprotein metabolism and atherosclerosis. Cardiovasc Res (2021) 117:1033–45. doi: 10.1093/cvr/cvaa252
12. Khalili P, Sundstrom J, Franklin SS, Jendle J, Lundin F, Jungner I, et al. Combined effects of brachial pulse pressure and sialic acid for risk of cardiovascular events during 40 years of follow-up in 37,843 individuals. J Hypertens (2012) 30:1718–24. doi: 10.1097/HJH.0b013e32835606ae
13. Lindberg G, Rastam L, Gullberg B, Eklund GA. Serum sialic acid concentration predicts both coronary heart disease and stroke mortality: Multivariate analysis including 54,385 men and women during 20.5 years follow-up. Int J Epidemiol (1992) 21:253–7. doi: 10.1093/ije/21.2.253
14. Serdar Z, Serdar A, Altin A, Eryilmaz U, Albayrak S. The relation between oxidant and antioxidant parameters and severity of acute coronary syndromes. Acta Cardiol (2007) 62:373–80. doi: 10.2143/AC.62.4.2022281
15. Serdar Z, Yesilbursa D, Dirican M, Sarandol E, Serdar A. Sialic acid and oxidizability of lipid and proteins and antioxidant status in patients with coronary artery disease. Cell Biochem Funct (2007) 25:655–64. doi: 10.1002/cbf.1369
16. Govindarajan S, Raghavan VM, Rao AC. Plasma myeloperoxidase and total sialic acid as prognostic indicators in acute coronary syndrome. J Clin Diagn Res (2016) 10:BC09–13. doi: 10.7860/JCDR/2016/20715.8347
17. Salomone OA, Crook JR, Hossein-Nia M, Holt D, Kaski JC. Serum sialic acid concentration is not associated with the extent or severity of coronary artery disease in patients with stable angina pectoris. Am Heart J (1998) 136:620–3. doi: 10.1016/S0002-8703(98)70008-0
18. Wu EB, Lumb P, Chambers JB, Crook MA. Plasma sialic acid and coronary artery atheromatous load in patients with stable chest pain. Atherosclerosis (1999) 145:261–6. doi: 10.1016/S0021-9150(99)00074-X
19. Tertov VV, Orekhov AN, Sobenin IA, Morrisett JD, Gotto AM Jr., Guevara JG Jr. Carbohydrate composition of protein and lipid components in sialic acid-rich and -poor low density lipoproteins from subjects with and without coronary artery disease. J Lipid Res (1993) 34:365–75. doi: 10.1016/S0022-2275(20)40729-1
20. Swaminathan N, Aladjem F. The monosaccharide composition and sequence of the carbohydrate moiety of human serum low density lipoproteins. Biochemistry (1976) 15:1516–22. doi: 10.1021/bi00652a024
21. Roghani A, Zannis VI. Mutagenesis of the glycosylation site of human ApoCIII. O-linked glycosylation is not required for ApoCIII secretion and lipid binding. J Biol Chem (1988) 263:17925–32. doi: 10.1016/S0021-9258(19)81305-4
22. Cubedo J, Padro T, Badimon L. Glycoproteome of human apolipoprotein a-I: N- and O-glycosylated forms are increased in patients with acute myocardial infarction. Transl Res (2014) 164:209–22. doi: 10.1016/j.trsl.2014.03.008
23. Huang J, Lee H, Zivkovic AM, Smilowitz JT, Rivera N, German JB, et al. Glycomic analysis of high density lipoprotein shows a highly sialylated particle. J Proteome Res (2014) 13:681–91. doi: 10.1021/pr4012393
24. Orekhov AN, Tertov VV, Mukhin DN, Mikhailenko IA. Modification of low density lipoprotein by desialylation causes lipid accumulation in cultured cells: Discovery of desialylated lipoprotein with altered cellular metabolism in the blood of atherosclerotic patients. Biochem Biophys Res Commun (1989) 162:206–11. doi: 10.1016/0006-291X(89)91982-7
25. Orekhov AN, Tertov VV, Sobenin IA, Smirnov VN, Via DP, Guevara J Jr., et al. Sialic acid content of human low density lipoproteins affects their interaction with cell receptors and intracellular lipid accumulation. J Lipid Res (1992) 33:805–17. doi: 10.1016/S0022-2275(20)41506-8
26. Tertov VV, Sobenin IA, Tonevitsky AG, Orekhov AN, Smirnov VN. Isolation of atherogenic modified (desialylated) low density lipoprotein from blood of atherosclerotic patients: Separation from native lipoprotein by affinity chromatography. Biochem Biophys Res Commun (1990) 167:1122–7. doi: 10.1016/0006-291X(90)90639-5
27. Hanson VA, Shettigar UR, Loungani RR, Nadijcka MD. Plasma sialidase activity in acute myocardial infarction. Am Heart J (1987) 114:59–63. doi: 10.1016/0002-8703(87)90307-3
28. Gracheva EV, Samovilova NN, Golovanova NK, Il'inskaya OP, Tararak EM, Malyshev PP, et al. Sialyltransferase activity of human plasma and aortic intima is enhanced in atherosclerosis. Biochim Biophys Acta (2002) 1586:123–8. doi: 10.1016/S0925-4439(01)00093-X
29. Orekhov AN, Bobryshev YV, Sobenin IA, Melnichenko AA, Chistiakov DA. Modified low density lipoprotein and lipoprotein-containing circulating immune complexes as diagnostic and prognostic biomarkers of atherosclerosis and type 1 diabetes macrovascular disease. Int J Mol Sci (2014) 15:12807–41. doi: 10.3390/ijms150712807
30. Ruelland A, Gallou G, Legras B, Paillard F, Cloarec L. LDL sialic acid content in patients with coronary artery disease. Clin Chim Acta (1993) 221:127–33. doi: 10.1016/0009-8981(93)90027-2
31. Tertov VV, Orekhov AN. Metabolism of native and naturally occurring multiple modified low density lipoprotein in smooth muscle cells of human aortic intima. Exp Mol Pathol (1997) 64:127–45. doi: 10.1006/exmp.1997.2216
32. Tertov VV, Sobenin IA, Gabbasov ZA, Popov EG, Jaakkola O, Solakivi T, et al. Multiple-modified desialylated low density lipoproteins that cause intracellular lipid accumulation. isolation, fractionation and characterization. Lab Invest (1992) 67:665–75.
33. Pentikainen MO, Oorni K, Ala-Korpela M, Kovanen PT. Modified LDL - trigger of atherosclerosis and inflammation in the arterial intima. J Intern Med (2000) 247:359–70. doi: 10.1046/j.1365-2796.2000.00655.x
34. Tertov VV, Sobenin IA, Orekhov AN. Characterization of desialylated low-density lipoproteins which cause intracellular lipid accumulation. Int J Tissue React (1992) 14:155–62.
35. Sukhorukov V, Gudelj I, Pucic-Bakovic M, Zakiev E, Orekhov A, Kontush A, et al. Glycosylation of human plasma lipoproteins reveals a high level of diversity, which directly impacts their functional properties. Biochim Biophys Acta Mol Cell Biol Lipids (2019) 1864:643–53. doi: 10.1016/j.bbalip.2019.01.005
36. Grewal T, Bartlett A, Burgess JW, Packer NH, Stanley KK. Desialylated LDL uptake in human and mouse macrophages can be mediated by a lectin receptor. Atherosclerosis (1996) 121:151–63. doi: 10.1016/0021-9150(95)05715-3
37. Orekhov AN, Tertov VV, Kabakov AE, Adamova I, Pokrovsky SN, Smirnov VN. Autoantibodies against modified low density lipoprotein. nonlipid factor of blood plasma that stimulates foam cell formation. Arterioscler Thromb (1991) 11:316–26. doi: 10.1161/01.ATV.11.2.316
38. Kacharava AG, Tertov VV, Orekhov AN. Autoantibodies against low-density lipoprotein and atherogenic potential of blood. Ann Med (1993) 25:551–5. doi: 10.1080/07853890.1993.12088583
39. Tertov VV, Sobenin IA, Orekhov AN, Jaakkola O, Solakivi T, Nikkari T. Characteristics of low density lipoprotein isolated from circulating immune complexes. Atherosclerosis (1996) 122:191–9. doi: 10.1016/0021-9150(95)05737-4
40. Harada LM, Carvalho MD, Passarelli M, Quintao EC. Lipoprotein desialylation simultaneously enhances the cell cholesterol uptake and impairs the reverse cholesterol transport system: In vitro evidences utilizing neuraminidase-treated lipoproteins and mouse peritoneal macrophages. Atherosclerosis (1998) 139:65–75. doi: 10.1016/S0021-9150(98)00057-4
41. Norata GD, Tsimikas S, Pirillo A, Catapano AL. Apolipoprotein c-III: From pathophysiology to pharmacology. Trends Pharmacol Sci (2015) 36:675–87. doi: 10.1016/j.tips.2015.07.001
42. Tg, Hdl Working Group of the Exome Sequencing Project NHL, Blood I, Crosby J, Peloso GM, Auer PL, Crosslin DR, et al. Loss-of-function mutations in APOC3, triglycerides, and coronary disease. N Engl J Med (2014) 371:22–31. doi: 10.1056/NEJMoa1307095
43. Jorgensen AB, Frikke-Schmidt R, Nordestgaard BG, Tybjaerg-Hansen A. Loss-of-function mutations in APOC3 and risk of ischemic vascular disease. N Engl J Med (2014) 371:32–41. doi: 10.1056/NEJMoa1308027
44. van Capelleveen JC, Bernelot Moens SJ, Yang X, Kastelein JJP, Wareham NJ, Zwinderman AH, et al. Apolipoprotein c-III levels and incident coronary artery disease risk: The EPIC-Norfolk prospective population study. Arterioscler Thromb Vasc Biol (2017) 37:1206–12. doi: 10.1161/ATVBAHA.117.309007
45. Yassine HN, Trenchevska O, Ramrakhiani A, Parekh A, Koska J, Walker RW, et al. The association of human apolipoprotein c-III sialylation proteoforms with plasma triglycerides. PloS One (2015) 10:e0144138. doi: 10.1371/journal.pone.0144138
46. Olivieri O, Chiariello C, Martinelli N, Castagna A, Speziali G, Girelli D, et al. Sialylated isoforms of apolipoprotein c-III and plasma lipids in subjects with coronary artery disease. Clin Chem Lab Med (2018) 56:1542–50. doi: 10.1515/cclm-2017-1099
47. Catapano AL. The distribution of apo c-II and apo c-III in very low density lipoproteins of normal and type IV subjects. Atherosclerosis (1980) 35:419–24. doi: 10.1016/0021-9150(80)90182-3
48. Kegulian NC, Ramms B, Horton S, Trenchevska O, Nedelkov D, Graham MJ, et al. ApoC-III glycoforms are differentially cleared by hepatic TRL (Triglyceride-rich lipoprotein) receptors. Arterioscler Thromb Vasc Biol (2019) 39:2145–56. doi: 10.1161/ATVBAHA.119.312723
49. Kowal RC, Herz J, Weisgraber KH, Mahley RW, Brown MS, Goldstein JL. Opposing effects of apolipoproteins e and c on lipoprotein binding to low density lipoprotein receptor-related protein. J Biol Chem (1990) 265:10771–9. doi: 10.1016/S0021-9258(18)87014-4
50. Foley EM, Gordts P, Stanford KI, Gonzales JC, Lawrence R, Stoddard N, et al. Hepatic remnant lipoprotein clearance by heparan sulfate proteoglycans and low-density lipoprotein receptors depend on dietary conditions in mice. Arterioscler Thromb Vasc Biol (2013) 33:2065–74. doi: 10.1161/ATVBAHA.113.301637
51. Windler E, Havel RJ. Inhibitory effects of c apolipoproteins from rats and humans on the uptake of triglyceride-rich lipoproteins and their remnants by the perfused rat liver. J Lipid Res (1985) 26:556–65. doi: 10.1016/S0022-2275(20)34342-X
52. Gordts PL, Nock R, Son NH, Ramms B, Lew I, Gonzales JC, et al. ApoC-III inhibits clearance of triglyceride-rich lipoproteins through LDL family receptors. J Clin Invest (2016) 126:2855–66. doi: 10.1172/JCI86610
53. Gaudet D, Brisson D, Tremblay K, Alexander VJ, Singleton W, Hughes SG, et al. Targeting APOC3 in the familial chylomicronemia syndrome. N Engl J Med (2014) 371:2200–6. doi: 10.1056/NEJMoa1400284
54. Holleboom AG, Karlsson H, Lin RS, Beres TM, Sierts JA, Herman DS, et al. Heterozygosity for a loss-of-function mutation in GALNT2 improves plasma triglyceride clearance in man. Cell Metab (2011) 14:811–8. doi: 10.1016/j.cmet.2011.11.005
55. Huang Y, Mahley RW. Apolipoprotein e: structure and function in lipid metabolism, neurobiology, and alzheimer's diseases. Neurobiol Dis (2014) 72 Pt A:3–12. doi: 10.1016/j.nbd.2014.08.025
56. Hatters DM, Peters-Libeu CA, Weisgraber KH. Apolipoprotein e structure: insights into function. Trends Biochem Sci (2006) 31:445–54. doi: 10.1016/j.tibs.2006.06.008
57. Hauser PS, Narayanaswami V and Ryan RO. Apolipoprotein e: From lipid transport to neurobiology. Prog Lipid Res (2011) 50:62–74. doi: 10.1016/j.plipres.2010.09.001
58. Flowers SA, Grant OC, Woods RJ, Rebeck GW. O-Glycosylation on cerebrospinal fluid and plasma apolipoprotein e differs in the lipid-binding domain. Glycobiology (2020) 30:74–85. doi: 10.1093/glycob/cwz084
59. Halim A, Ruetschi U, Larson G and Nilsson J. LC-MS/MS characterization of O-glycosylation sites and glycan structures of human cerebrospinal fluid glycoproteins. J Proteome Res (2013) 12:573–84. doi: 10.1021/pr300963h
60. Lee Y, Kockx M, Raftery MJ, Jessup W, Griffith R, Kritharides L. Glycosylation and sialylation of macrophage-derived human apolipoprotein e analyzed by SDS-PAGE and mass spectrometry: Evidence for a novel site of glycosylation on Ser290. Mol Cell Proteomics (2010) 9:1968–81. doi: 10.1074/mcp.M900430-MCP200
61. Marmillot P, Rao MN, Liu QH, Lakshman MR. Desialylation of human apolipoprotein e decreases its binding to human high-density lipoprotein and its ability to deliver esterified cholesterol to the liver. Metabolism (1999) 48:1184–92. doi: 10.1016/S0026-0495(99)90136-1
62. Ke LY, Chan HC, Chen CC, Chang CF, Lu PL, Chu CS, et al. Increased APOE glycosylation plays a key role in the atherogenicity of L5 low-density lipoprotein. FASEB J (2020) 34:9802–13. doi: 10.1096/fj.202000659R
63. Akyol S, Lu J, Akyol O, Akcay F, Armutcu F, Ke LY, et al. The role of electronegative low-density lipoprotein in cardiovascular diseases and its therapeutic implications. Trends Cardiovasc Med (2017) 27:239–46. doi: 10.1016/j.tcm.2016.11.002
64. Ke LY, Stancel N, Bair H, Chen CH. The underlying chemistry of electronegative LDL's atherogenicity. Curr Atheroscler Rep (2014) 16:428. doi: 10.1007/s11883-014-0428-y
65. Pu Q, Yu C. Glycosyltransferases, glycosylation and atherosclerosis. Glycoconj J (2014) 31:605–11. doi: 10.1007/s10719-014-9560-8
66. van den Boogert MAW, Rader DJ, Holleboom AG. New insights into the role of glycosylation in lipoprotein metabolism. Curr Opin Lipidol (2017) 28:502–6. doi: 10.1097/MOL.0000000000000461
67. Varki A, Gagneux P. Multifarious roles of sialic acids in immunity. Ann N Y Acad Sci (2012) 1253:16–36. doi: 10.1111/j.1749-6632.2012.06517.x
68. Zhou JY, Cobb BA. Glycans in immunologic health and disease. Annu Rev Immunol (2021) 39:511–36. doi: 10.1146/annurev-immunol-101819-074237
69. Hugonnet M, Singh P, Haas Q, von Gunten S. The distinct roles of sialyltransferases in cancer biology and onco-immunology. Front Immunol (2021) 12:799861. doi: 10.3389/fimmu.2021.799861
70. Bourguet E, Figurska S, Fra Czek MM. Human neuraminidases: Structures and stereoselective inhibitors. J Med Chem (2022) 65:3002–25. doi: 10.1021/acs.jmedchem.1c01612
71. Keppler OT, Hinderlich S, Langner J, Schwartz-Albiez R, Reutter W, Pawlita M. UDP-GlcNAc 2-epimerase: A regulator of cell surface sialylation. Science (1999) 284:1372–6. doi: 10.1126/science.284.5418.1372
72. Guo S, Tian H, Dong R, Yang N, Zhang Y, Yao S, et al. Exogenous supplement of n-acetylneuraminic acid ameliorates atherosclerosis in apolipoprotein e-deficient mice. Atherosclerosis (2016) 251:183–91. doi: 10.1016/j.atherosclerosis.2016.05.032
73. Hou P, Hu S, Wang J, Yang Z, Yin J, Zhou G, et al. Exogenous supplement of n-acetylneuraminic acid improves macrophage reverse cholesterol transport in apolipoprotein e-deficient mice. Lipids Health Dis (2019) 18:24. doi: 10.1186/s12944-019-0971-1
74. Miyagi T, Yamaguchi K. Mammalian sialidases: physiological and pathological roles in cellular functions. Glycobiology (2012) 22:880–96. doi: 10.1093/glycob/cws057
75. Glanz VY, Myasoedova VA, Grechko AV, Orekhov AN. Sialidase activity in human pathologies. Eur J Pharmacol (2019) 842:345–50. doi: 10.1016/j.ejphar.2018.11.014
76. Cross AS, Hyun SW, Miranda-Ribera A, Feng C, Liu A, Nguyen C, et al. NEU1 and NEU3 sialidase activity expressed in human lung microvascular endothelia: NEU1 restrains endothelial cell migration, whereas NEU3 does not. J Biol Chem (2012) 287:15966–80. doi: 10.1074/jbc.M112.346817
77. Feng C, Zhang L, Almulki L, Faez S, Whitford M, Hafezi-Moghadam A, et al. Endogenous PMN sialidase activity exposes activation epitope on CD11b/CD18 which enhances its binding interaction with ICAM-1. J Leukoc Biol (2011) 90:313–21. doi: 10.1189/jlb.1210708
78. Igdoura SA, Gafuik C, Mertineit C, Saberi F, Pshezhetsky AV, Potier M, et al. Cloning of the cDNA and gene encoding mouse lysosomal sialidase and correction of sialidase deficiency in human sialidosis and mouse SM/J fibroblasts. Hum Mol Genet (1998) 7:115–21. doi: 10.1093/hmg/7.1.115
79. Pshezhetsky AV, Richard C, Michaud L, Igdoura S, Wang S, Elsliger MA, et al. Cloning, expression and chromosomal mapping of human lysosomal sialidase and characterization of mutations in sialidosis. Nat Genet (1997) 15:316–20. doi: 10.1038/ng0397-316
80. Gayral S, Garnotel R, Castaing-Berthou A, Blaise S, Fougerat A, Berge E, et al. Elastin-derived peptides potentiate atherosclerosis through the immune Neu1-PI3Kgamma pathway. Cardiovasc Res (2014) 102:118–27. doi: 10.1093/cvr/cvt336
81. Fulop T Jr., Larbi A, Fortun A, Robert L, Khalil A. Elastin peptides induced oxidation of LDL by phagocytic cells. Pathol Biol (Paris) (2005) 53:416–23. doi: 10.1016/j.patbio.2004.12.023
82. Robert L, Jacob MP, Frances C, Godeau G, Hornebeck W. Interaction between elastin and elastases and its role in the aging of the arterial wall, skin and other connective tissues. A review. Mech Ageing Dev (1984) 28:155–66. doi: 10.1016/0047-6374(84)90015-0
83. Mochizuki S, Brassart B, Hinek A. Signaling pathways transduced through the elastin receptor facilitate proliferation of arterial smooth muscle cells. J Biol Chem (2002) 277:44854–63. doi: 10.1074/jbc.M205630200
84. Maurice P, Blaise S, Gayral S, Debelle L, Laffargue M, Hornebeck W, et al. Elastin fragmentation and atherosclerosis progression: The elastokine concept. Trends Cardiovasc Med (2013) 23:211–21. doi: 10.1016/j.tcm.2012.12.004
85. Duca L, Blanchevoye C, Cantarelli B, Ghoneim C, Dedieu S, Delacoux F, et al. The elastin receptor complex transduces signals through the catalytic activity of its neu-1 subunit. J Biol Chem (2007) 282:12484–91. doi: 10.1074/jbc.M609505200
86. Rusciani A, Duca L, Sartelet H, Chatron-Colliet A, Bobichon H, Ploton D, et al. Elastin peptides signaling relies on neuraminidase-1-dependent lactosylceramide generation. PloS One (2010) 5:e14010. doi: 10.1371/journal.pone.0014010
87. Seyrantepe V, Hinek A, Peng J, Fedjaev M, Ernest S, Kadota Y, et al. Enzymatic activity of lysosomal carboxypeptidase (cathepsin) a is required for proper elastic fiber formation and inactivation of endothelin-1. Circulation (2008) 117:1973–81. doi: 10.1161/CIRCULATIONAHA.107.733212
88. Yogalingam G, Bonten EJ, van de Vlekkert D, Hu H, Moshiach S, Connell SA, et al. Neuraminidase 1 is a negative regulator of lysosomal exocytosis. Dev Cell (2008) 15:74–86. doi: 10.1016/j.devcel.2008.05.005
89. de Geest N, Bonten E, Mann L, de Sousa-Hitzler J, Hahn C, d'Azzo A. Systemic and neurologic abnormalities distinguish the lysosomal disorders sialidosis and galactosialidosis in mice. Hum Mol Genet (2002) 11:1455–64. doi: 10.1093/hmg/11.12.1455
90. White EJ, Gyulay G, Lhotak S, Szewczyk MM, Chong T, Fuller MT, et al. Sialidase down-regulation reduces non-HDL cholesterol, inhibits leukocyte transmigration, and attenuates atherosclerosis in ApoE knockout mice. J Biol Chem (2018) 293:14689–706. doi: 10.1074/jbc.RA118.004589
91. Carrillo MB, Milner CM, Ball ST, Snoek M, Campbell RD. Cloning and characterization of a sialidase from the murine histocompatibility-2 complex: Low levels of mRNA and a single amino acid mutation are responsible for reduced sialidase activity in mice carrying the Neu1a allele. Glycobiology (1997) 7:975–86. doi: 10.1093/glycob/7.7.975
92. Champigny MJ, Mitchell M, Fox-Robichaud A, Trigatti BL, Igdoura SA. A point mutation in the neu1 promoter recruits an ectopic repressor, Nkx3.2 and results in a mouse model of sialidase deficiency. Mol Genet Metab (2009) 97:43–52. doi: 10.1016/j.ymgme.2009.01.004
93. Heimerl M, Sieve I, Ricke-Hoch M, Erschow S, Battmer K, Scherr M, et al. Neuraminidase-1 promotes heart failure after ischemia/reperfusion injury by affecting cardiomyocytes and invading monocytes/macrophages. Basic Res Cardiol (2020) 115:62. doi: 10.1007/s00395-020-00821-z
94. Demina EP, Smutova V, Pan X, Fougerat A, Guo T, Zou C, et al. Neuraminidases 1 and 3 trigger atherosclerosis by desialylating low-density lipoproteins and increasing their uptake by macrophages. J Am Heart Assoc (2021) 10:e018756. doi: 10.1161/JAHA.120.018756
95. Seyrantepe V, Canuel M, Carpentier S, Landry K, Durand S, Liang F, et al. Mice deficient in Neu4 sialidase exhibit abnormal ganglioside catabolism and lysosomal storage. Hum Mol Genet (2008) 17:1556–68. doi: 10.1093/hmg/ddn043
96. Yamaguchi K, Shiozaki K, Moriya S, Koseki K, Wada T, Tateno H, et al. Reduced susceptibility to colitis-associated colon carcinogenesis in mice lacking plasma membrane-associated sialidase. PloS One (2012) 7:e41132. doi: 10.1371/journal.pone.0041132
97. Bocquet O, Wahart A, Sarazin T, Vincent E, Schneider C, Fougerat A, et al. Adverse effects of oseltamivir phosphate therapy on the liver of LDLR-/- mice without any benefit on atherosclerosis and thrombosis. J Cardiovasc Pharmacol (2021) 77:660–72. doi: 10.1097/FJC.0000000000001002
98. Zhang Y, Albohy A, Zou Y, Smutova V, Pshezhetsky AV, Cairo CW. Identification of selective inhibitors for human neuraminidase isoenzymes using C4,C7-modified 2-deoxy-2,3-didehydro-N-acetylneuraminic acid (DANA) analogues. J Med Chem (2013) 56:2948–58. doi: 10.1021/jm301892f
99. Magesh S, Moriya S, Suzuki T, Miyagi T, Ishida H, Kiso M. Design, synthesis, and biological evaluation of human sialidase inhibitors. part 1: Selective inhibitors of lysosomal sialidase (NEU1). Bioorg Med Chem Lett (2008) 18:532–7. doi: 10.1016/j.bmcl.2007.11.084
100. Sperandio M, Gleissner CA, Ley K. Glycosylation in immune cell trafficking. Immunol Rev (2009) 230:97–113. doi: 10.1111/j.1600-065X.2009.00795.x
101. Sage AP, Mallat Z. Sialyltransferase activity and atherosclerosis. Circ Res (2014) 114:935–7. doi: 10.1161/CIRCRESAHA.114.303480
102. Johnson JL, Jones MB, Ryan SO, Cobb BA. The regulatory power of glycans and their binding partners in immunity. Trends Immunol (2013) 34:290–8. doi: 10.1016/j.it.2013.01.006
103. Xu C, Wang S, Wu Y, Sun X, Yang D, Wang S. Recent advances in understanding the roles of sialyltransferases in tumor angiogenesis and metastasis. Glycoconj J (2021) 38:119–27. doi: 10.1007/s10719-020-09967-3
104. Matsui T, Titani K, Mizuochi T. Structures of the asparagine-linked oligosaccharide chains of human von willebrand factor. occurrence of blood group a, b, and H(O) structures. J Biol Chem (1992) 267:8723–31. doi: 10.1016/S0021-9258(19)50338-6
105. Ellies LG, Ditto D, Levy GG, Wahrenbrock M, Ginsburg D, Varki A, et al. Sialyltransferase ST3Gal-IV operates as a dominant modifier of hemostasis by concealing asialoglycoprotein receptor ligands. Proc Natl Acad Sci USA (2002) 99:10042–7. doi: 10.1073/pnas.142005099
106. Song J, Xue C, Preisser JS, Cramer DW, Houck KL, Liu G, et al. Association of single nucleotide polymorphisms in the ST3GAL4 gene with VWF antigen and factor VIII activity. PloS One (2016) 11:e0160757. doi: 10.1371/journal.pone.0160757
107. Ellies LG, Sperandio M, Underhill GH, Yousif J, Smith M, Priatel JJ, et al. Sialyltransferase specificity in selectin ligand formation. Blood (2002) 100:3618–25. doi: 10.1182/blood-2002-04-1007
108. Sperandio M, Frommhold D, Babushkina I, Ellies LG, Olson TS, Smith ML, et al. Alpha 2,3-sialyltransferase-IV is essential for l-selectin ligand function in inflammation. Eur J Immunol (2006) 36:3207–15. doi: 10.1002/eji.200636157
109. Yang WH, Nussbaum C, Grewal PK, Marth JD, Sperandio M. Coordinated roles of ST3Gal-VI and ST3Gal-IV sialyltransferases in the synthesis of selectin ligands. Blood (2012) 120:1015–26. doi: 10.1182/blood-2012-04-424366
110. Frommhold D, Ludwig A, Bixel MG, Zarbock A, Babushkina I, Weissinger M, et al. Sialyltransferase ST3Gal-IV controls CXCR2-mediated firm leukocyte arrest during inflammation. J Exp Med (2008) 205:1435–46. doi: 10.1084/jem.20070846
111. Price DT, Loscalzo J. Cellular adhesion molecules and atherogenesis. Am J Med (1999) 107:85–97. doi: 10.1016/S0002-9343(99)00153-9
112. Doring Y, Noels H, Mandl M, Kramp B, Neideck C, Lievens D, et al. Deficiency of the sialyltransferase St3Gal4 reduces Ccl5-mediated myeloid cell recruitment and arrest: Short communication. Circ Res (2014) 114:976–81. doi: 10.1161/CIRCRESAHA.114.302426
113. Bannert N, Craig S, Farzan M, Sogah D, Santo NV, Choe H, et al. Sialylated O-glycans and sulfated tyrosines in the NH2-terminal domain of CC chemokine receptor 5 contribute to high affinity binding of chemokines. J Exp Med (2001) 194:1661–73. doi: 10.1084/jem.194.11.1661
115. Zhou JY, Oswald DM, Oliva KD, Kreisman LSC, Cobb BA. The glycoscience of immunity. Trends Immunol (2018) 39:523–35. doi: 10.1016/j.it.2018.04.004
116. Saade S, Cazier JB, Ghassibe-Sabbagh M, Youhanna S, Badro DA, Kamatani Y, et al. Large Scale association analysis identifies three susceptibility loci for coronary artery disease. PloS One (2011) 6:e29427. doi: 10.1371/journal.pone.0029427
117. Kooner JS, Saleheen D, Sim X, Sehmi J, Zhang W, Frossard P, et al. Genome-wide association study in individuals of south Asian ancestry identifies six new type 2 diabetes susceptibility loci. Nat Genet (2011) 43:984–9. doi: 10.1038/ng.921
118. Lu S, Xie Y, Lin K, Li S, Zhou Y, Ma P, et al. Genome-wide association studies-derived susceptibility loci in type 2 diabetes: Confirmation in a Chinese population. Clin Invest Med (2012) 35:E327. doi: 10.25011/cim.v35i5.18706
119. Zhang J, Liu Y, Deng X, Chen L, Yang X, Yu C. ST6GAL1 negatively regulates monocyte transendothelial migration and atherosclerosis development. Biochem Biophys Res Commun (2018) 500:249–55. doi: 10.1016/j.bbrc.2018.04.053
120. Holdbrooks AT, Ankenbauer KE, Hwang J, Bellis SL. Regulation of inflammatory signaling by the ST6Gal-I sialyltransferase. PloS One (2020) 15:e0241850. doi: 10.1371/journal.pone.0241850
121. Oswald DM, Jones MB, Cobb BA. Modulation of hepatocyte sialylation drives spontaneous fatty liver disease and inflammation. Glycobiology (2020) 30:346–59. doi: 10.1093/glycob/cwz096
122. Oswald DM, Zhou JY, Jones MB, Cobb BA. Disruption of hepatocyte sialylation drives a T cell-dependent pro-inflammatory immune tone. Glycoconj J (2020) 37:395–407. doi: 10.1007/s10719-020-09918-y
123. Wang Q, Chen Z, Peng X, Zheng Z, Le A, Guo J, et al. Neuraminidase 1 exacerbating aortic dissection by governing a pro-inflammatory program in macrophages. Front Cardiovasc Med (2021) 8:788645. doi: 10.3389/fcvm.2021.788645
124. Kawecki C, Bocquet O, Schmelzer CEH, Heinz A, Ihling C, Wahart A, et al. Identification of CD36 as a new interaction partner of membrane NEU1: Potential implication in the pro-atherogenic effects of the elastin receptor complex. Cell Mol Life Sci (2019) 76:791–807. doi: 10.1007/s00018-018-2978-6
125. Febbraio M, Podrez EA, Smith JD, Hajjar DP, Hazen SL, Hoff HF, et al. Targeted disruption of the class b scavenger receptor CD36 protects against atherosclerotic lesion development in mice. J Clin Invest (2000) 105:1049–56. doi: 10.1172/JCI9259
126. Podrez EA, Byzova TV, Febbraio M, Salomon RG, Ma Y, Valiyaveettil M, et al. Platelet CD36 links hyperlipidemia, oxidant stress and a prothrombotic phenotype. Nat Med (2007) 13:1086–95. doi: 10.1038/nm1626
127. Menni C, Gudelj I, Macdonald-Dunlop E, Mangino M, Zierer J, Besic E, et al. Glycosylation profile of immunoglobulin G is cross-sectionally associated with cardiovascular disease risk score and subclinical atherosclerosis in two independent cohorts. Circ Res (2018) 122:1555–64. doi: 10.1161/CIRCRESAHA.117.312174
128. Pagan JD, Kitaoka M, Anthony RM. Engineered sialylation of pathogenic antibodies In vivo attenuates autoimmune disease. Cell (2018) 172:564–77. doi: 10.1016/j.cell.2017.11.041
129. Biermann MH, Griffante G, Podolska MJ, Boeltz S, Sturmer J, Munoz LE, et al. Sweet but dangerous - the role of immunoglobulin G glycosylation in autoimmunity and inflammation. Lupus (2016) 25:934–42. doi: 10.1177/0961203316640368
130. Harre U, Lang SC, Pfeifle R, Rombouts Y, Fruhbeisser S, Amara K, et al. Glycosylation of immunoglobulin G determines osteoclast differentiation and bone loss. Nat Commun (2015) 6:6651. doi: 10.1038/ncomms7651
131. Nioi P, Sigurdsson A, Thorleifsson G, Helgason H, Agustsdottir AB, Norddahl GL, et al. Variant ASGR1 associated with a reduced risk of coronary artery disease. N Engl J Med (2016) 374:2131–41. doi: 10.1056/NEJMoa1508419
132. Xu Y, Tao J, Yu X, Wu Y, Chen Y, You K, et al. Hypomorphic ASGR1 modulates lipid homeostasis via INSIG1-mediated SREBP signaling suppression. JCI Insight (2021) 6. doi: 10.1172/jci.insight.147038
133. Kawanishi K, Dhar C, Do R, Varki N, Gordts P, Varki A. Human species-specific loss of CMP-n-acetylneuraminic acid hydroxylase enhances atherosclerosis via intrinsic and extrinsic mechanisms. Proc Natl Acad Sci USA (2019) 116:16036–45. doi: 10.1073/pnas.1902902116
134. Hayakawa T, Aki I, Varki A, Satta Y, Takahata N. Fixation of the human-specific CMP-n-acetylneuraminic acid hydroxylase pseudogene and implications of haplotype diversity for human evolution. Genetics (2006) 172:1139–46. doi: 10.1534/genetics.105.046995
135. Chou HH, Takematsu H, Diaz S, Iber J, Nickerson E, Wright KL, et al. A mutation in human CMP-sialic acid hydroxylase occurred after the homo-pan divergence. Proc Natl Acad Sci USA (1998) 95:11751–6. doi: 10.1161/ATVBAHA.120.315280
Keywords: atherosclerosis, sialic acid, neuraminidase, sialyltransferase, lipoprotein, selectin
Citation: Yu L, Peng J and Mineo C (2022) Lipoprotein sialylation in atherosclerosis: Lessons from mice. Front. Endocrinol. 13:953165. doi: 10.3389/fendo.2022.953165
Received: 25 May 2022; Accepted: 15 August 2022;
Published: 06 September 2022.
Edited by:
Xunde Xian, Peking University, ChinaReviewed by:
Brian A. Cobb, Case Western Reserve University, United States;Joseph T. Y. Lau, University at Buffalo, United StatesCopyright © 2022 Yu, Peng and Mineo. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Chieko Mineo, Chieko.Mineo@UTSouthwestern.edu